Daytona Helmets D.O.T. Carbon Fiber Slim Line Motorcycle Helmet Size Medium Meets And Exceeds D.O.T. Safety Standards FMVSS 218. The Smallest D.O.T. Half Shell Helmet Ever Made!! With Three Different Shell Sizes You're Sure To Get That Proportionate Fit!! Moisture Wicking Fabric Keeping Your Head Cooler And More Comfortable. 100% Carbon Fiber.